This invention relates to hand-pump spray bottles for dispensing a liquid in a jet or atomization mode and, more particularly, to such a bottle having a novel air inlet unit that prevents the liquid contents from leaking out of the air inlet unit when the container is operated at an orientation that causes the air inlet unit to be covered with liquid.
Hand-pump spray bottles have become increasingly popular to eliminate the use of pressurized cans due to environmental concerns and high cost. Over one billion spray bottles are sold each year to dispense such liquids as glass cleaners, bathroom cleaners, waxes, and oils.
These spray bottles have a feed tube with an open end entrance that extends into the liquid contents and serves as a conduit to the hand pump. There is an air inlet port, usually located in the hand pump, that admits air into the bottle when the pump is operated. This admitted air replaces the liquid that is dispensed, in order to maintain approximately atmospheric pressure within the bottle. These spray bottles operate well under some conditions. However, if the feed tube entrance is within the liquid and the air inlet port is covered with liquid, as would occur when the bottle is operated at certain commonly encountered orientations, the hand pump will dispense the liquid satisfactorily but liquid will leak out of the air inlet port. This leakage occurs with conventional spray bottles as well as with any of the numerous bottles that can operate in the inverted position, such as described in U.S. Pat. Nos. 3,733,013; 4,775,070; and 5,624,060. This leakage is highly undesirable for any liquid since it is unpleasant to wet the hand, and it is a waste of product. Any leakage, even the smallest amount, is completely unacceptable for any caustic liquids.
It is the principal object of this invention to provide an air inlet unit that will admit air to a hand-pump spray bottle but will prevent leakage of the liquid contents when the bottle is operated in an orientation where the air inlet port is covered with liquid.
It is another object of this invention to admit sufficient air to maintain the air pressure within the bottle at a level that will prevent it from collapsing any appreciable amount.
It is yet another object of this invention for the air inlet unit to operate without any moving parts.
Still another object of this invention is to provide an air inlet unit that will increase the cost of the entire bottle assembly only a negligible amount.
It is still another object of this invention to provide a single design for the air inlet unit that will operate with any dispensable liquid.
It is a further object of this invention to incorporate the air inlet unit into the hand pump without any additional assembly steps.
Other objects and advantages of this invention will become apparent from the teachings of the following specification and appended drawings.